The present disclosure relates to a conveying roller unit that conveys a sheet member by rotating in contact with the sheet member, a sheet conveying device, and an image processing apparatus including the sheet conveying device.
A conventional image forming apparatus such as a copy machine, a printer, or the like includes a sheet conveying device. The sheet conveying device takes out and conveys a sheet member stored in a sheet feed cassette. The sheet conveying device includes a rotary roller (conveying roller) that rotates in contact with a sheet member. When a rotational driving force in one direction is transferred from a motor or the like to the rotary roller, the rotary roller conveys the sheet member in a predetermined direction. A rotation shaft of the rotary roller is connected to a drive shaft that transfers a rotational driving force of the motor, by means of a coupling.
As such a sheet conveying device, a device is known which includes a mechanism that allows a deteriorated rotary roller to be easily replaced. A conventional typical sheet feeder includes a fixing mechanism that fixes a sheet feed roller to a drive shaft in a state where the sheet feed roller is fitted to the drive shaft, and replacement of the sheet feed roller is allowed by releasing the fixing by the fixing mechanism.
In addition, a coupling connection mechanism is known which connects a rotation shaft of a rotary roller to a drive shaft that transfers a rotational driving force from a motor, by means of a coupling. A typical coupling connection mechanism includes an elastic member provided on a rotation shaft of a rotary roller, such as a spring, and the rotation shaft is supported via the elastic member. Thus, when the rotation shaft of the rotary roller is pressed in a direction in which the elastic member is contracted, the elastic member is contracted, and the rotation shaft is retracted into the rotary roller. Therefore, the user is allowed to disconnect the rotation shaft from the coupling connection mechanism by pressing the rotation shaft toward the inner side of the rotary roller. Accordingly, the user is allowed to easily remove the rotary roller.
The coupling connection mechanism requires a fixing mechanism to restrict the rotation shaft from moving in an axial direction by the elastic member. As the fixing mechanism, it is possible to use an elastic engagement claw. The elastic engagement claw is a mechanism that mechanically fixes the rotation shaft by a claw portion being engaged with a recess formed in a member biased by elasticity. The mechanism is referred to as snap fit.